Can a court re-open a finalized divorce to provide an unrepresented party equitable distribution ?

I am 62 years old. My ex-husband and I married at 20 (in 1975), and separated 6 years later. Approximately, 5-6 years after our separation, he (represented by an attorney, I not) presented me with papers to sign and I did. My question is two-fold: I believe that at the time I was presented with those papers, he owned property and other assets and I never received equitable distribution. The divorce was filed in New York County. My husband's name is Scott Clifford Marden, my name is Sherley Marden, nee Ayala and the attorney representing him was Tom Burke. Can the court right this wrong? My second question concerns social security. I no longer have a copy of the divorce decree so I am not sure exactly how long we were married, recall I said he presented me with the papers approximately 5-6 years after our separation. How can I obtain a copy of the divorce decree and am I entitled to collect social security from him?